ce508a3c29
It can be tricky to troubleshoot qos-test when a test won't execute. Add an explanation of how to trace qgraph node connectivity and find which node has the problem. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20210412143437.727560-3-stefanha@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>